2001 GMC Sierra Engine Idles rough then dies

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by hoosierfarmer21, Oct 3, 2013.

  1. hoosierfarmer21

    hoosierfarmer21 New Member

    I recently purchased a 2001 Sierra 1500 with the 5.3 L. I was driving along yesterday when the truck seemed to start to surging going down the road. I then got stopped in construction traffic a 1/2 mile down the road and the truck almost died in the middle of the road. I pulled into a parking lot and the truck then died pulling into a spot. The truck would start up fine and would idle at around 1000 RPM, then the idle would gradually drop down to 500 RPM and then lessen some more and die. From the time I started the truck do it dying would estimate to be around 1 minute. I was able to start it and keep it running and limp it back to the farm. Ran fine while driving to the farm except that it did do some more surging. Came home and did some research and figured I would try and clean up the throttle body and the mass air flow sensor so this morning I went and bought the cleaners from Autozone to do so. Went to the truck and started it up, idled at 1000 RPM for about 30 seconds then RPMs dropped and then died. Started again but only ran for maybe 5-10 seconds this time before dying.
    Should I be looking at the fuel pump now? Engine light is on but haven't had a chance to get a code reader on it since I can't drive it to a shop to have them check it out.
    Thanks for any and all help
  2. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    Likely is a fuel pressure issue. The truck should never run below 750 rpm because that's below the normal idle range. Definitely find a way to check the codes even if you just get a cheapo OBDII adapter from amazon and use the Torque app it will let you see the codes. That what I use on my truck.
  3. dsfloyd

    dsfloyd Epic Member 5+ Years ROTM Winner 1000 Posts

    I would get the light checked but would also lean towards looking at the fuel pump/regulator. Also try and check the fuel pressure. See if it you are losing pressure as it starts to die.

    Looks like [MENTION=52248]Conlan Rose[/MENTION] beat me too it.
  4. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    x3 on the fuel issue. Pull the vacuum line off of the regulator. (located on the driver side fuel rail on the top side of the motor, may have to pull the "Vortec" cover off to get to it) If fuel comes out of where the vacuum line plugs into the regulator then your regulator is bad.
  5. j cat

    j cat Epic Member 5+ Years 1000 Posts

    the fuel pressures with the engine on should be above 53PSI. engine off ignition to on 60-65 psi and should hold for while. now if the pressure falls rapidly then the regulator or injector leaking.

    I think your vehicle also has a PCV and hoses, make sure they are good and no cracks . replace the PCV if old.

    sometimes this can be the cranksensor . checking the codes post here what pressures/codes found.

    normal idle should be about 600-675RPM . in gear or not. this is controlled by the IAC. throttle body cleaner cleaning of this parts is required from time to time. you will need to remove the IAC to clean out the bore hole. do not use too much cleaner . use a hair dryer to evap excess throttle body solvents before starting.

    tooth brush works good to loosen the carbon then wipe down with a cloth.
  6. 00chevy53

    00chevy53 Rockstar 100 Posts

    Had a similar issue a few years ago and is probably your 02sensors going bad... Scan it to be sure but willing to bet 02 sensors is the culprit
  7. hoosierfarmer21

    hoosierfarmer21 New Member

    Finally got around to working on the truck. It died probably 3 times before I was able to load it on a trailer. Ran fine once on the trailer. Check fuel pressure while running and had around 50 PSI. Backed off the trailer and drove it around for 15 minutes. Came back and truck sit for an hour and now truck won't start. Checked fuel pressure, 0 PSI. So we decided to change the fuel pump. Take bed off, remove and replace with new pump from AutoZone. Start truck up and it runs fine for 15 minutes. Shut it off to put bed back on. Have a couple beers then go to leave and truck won't start. Doing what it did all along. Turn key on and you can't hear the fuel pump turn on. But it might do this 20 times and on the 21st time you will turn the key on and the pump will activate and the truck will start. So my question is, what tells the pump to come on or shut off? Like if you turn the key on but don't actually start the truck, the pump will turn on but shuts off because you don't start the truck?
    Working on finding a code reader to see what if any codes are present. Thanks guys!
  8. j cat

    j cat Epic Member 5+ Years 1000 Posts

    when you replace a fuel pump on a vehicle this old the relay need be replaced. also how did you connect the new pump to the existing OEM carbody wiring ? what manufacturer did you use for the pump ? I hope not an AIRTEX !

  9. hoosierfarmer21

    hoosierfarmer21 New Member

    It was an Airtex pump. They didn't have the A/C Delco pump in stock. There was a new connector that we had to splice into the truck wires to fit the new pump. We didn't change the relay but swapped it with the horn relay afterwards, both had the same numbers on them, and the problem was still there.
    Forgot to add that we hooked the old pump to a power source afterwards and it works so it may not have been the pump to begin with.
  10. j cat

    j cat Epic Member 5+ Years 1000 Posts

    if they gave me an airtex pump for free I would say no......

    the wires need be soldered. you must use the proper wire soldering and sealing to do any wire work in that area. the ground connection to the frame rail in the fuel tank area need be cleaned and secure.

    the old pump may run but with not the correct pressure. also when they start to go you can get them to run by tapping them ...

    so the engine ran for 15 min you checked the pressure all was good then the pump died ...not too bad for airtex. some had them not work out of the box.................

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